Some chemists might find it surprising to learn that phase-transfer catalysis has been used for nearly 40 years to transfer inorganic acids to nonpolar organic phases to perform a variety of reactions including addition of hydrogen halides across double bonds, ether cleavage, acid-catalyzed aldol condensations and hydrolysis.
A US patent application was published this month that uses TBAB to transfer HCl into toluene, presumably by hydrogen bonding. Once in dissolved in toluene, the dehydrated HCl is MUCH more active than when dissolved in a concentrated aqueous solution and the HCl is able to cleave the labile trityl ether at ambient temperature to form the alcohol and trityl chloride byproduct. After deprotection, the alcohol attacks the protected boronate to cyclize into a 5-membered ring and liberate pinacol as the byproduct.
At PTC Organics, we have done quite a few PTC-acid reactions in very high yield. If your company can benefit from highly specialized expertise in acid-catalyzed reactions or stoichiometric acid reactions, now contact Marc Halpern of PTC Organics Inc. to explore improving your process performance and process R&D efficiency through a PTC Process Consulting Agreement.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).
